Square has released some new screenshots for the Tokyo Game Show. It looks like the environments are polygonal, so you should be able to rotate them like in Final Fantasy Tactics.

Oh, and two screenshots from Seiken Densetsu 3 were included in the package, but they don't have the Super Famicom's resolution of 256x224. Instead, their resolution is 512x384, which is exactly twice the DS's resolution of 256x192.

This could be a clue.